1. Field
Example embodiments relate to a method for processing an image that enhances an image quality of an image using a plurality of images under different exposure conditions.
2. Description of the Related Art
When capturing an image with an image capturing apparatus such as a camera under low luminance conditions, such as a dark environment with a relatively low illumination, two types of an image quality degradation issues may arise. A first such issue arises when capturing is performed by setting a long exposure time to achieve a sufficient exposure. As a shutter speed may become longer, motion blur may occur due to shaking of the image capturing apparatus or a motion of an object. A second such issue arises when capturing is performed by setting a short exposure A strong noise may occur in an overall image through amplification of a noise component in a dark image.
To solve the image quality degradation issue of an image captured under the low luminance conditions, technology for removing motion blur and high-efficiency technology for removing noise, and the like, have been developed based on a single resulting image.
Recently, technology for capturing a plurality of images rather than a single image to process the plurality of images through synthesis is being developed. For example, research is being conducted into technology for solving the image quality degradation issue using an image captured under different exposure conditions. Such technology for processing an image may be utilized in image editing to enhance an image quality of an image captured under the low luminance conditions or to achieve a brightness or a color sense for fine art photography.
An image output from an image signal processor (ISP) currently being used extensively may be an image, for example, YCbCr422, obtained by sub-sampling or down-sampling components of a portion of channels, rather than a full color channel image, for example, YCbCr444. Generally, to enhance an image quality of a YCbCr422 image, the YCbCr422 image may be converted to a YCbCr444 image on which image processing is to be performed subsequently, and the image-processed YCbCr444 image may be re-converted to the YCbCr422 image. Nonetheless, there is still a need for a technology for processing the image to deal with such issues, because the process of converting the images may not only be time-consuming but also consume a significant portion of system resources, and cause the image quality degradation issue.